For adapting to the multistate characteristics of the intersection traffic flow, the intersection arrival headway is
accurately fitted by using the expectation maximization algorithm and the dense mixture Gamma distribution function, and
the probabilities of arrival traffic volume at intersection entrance are counted. Taking a two-phase full-actuated controlled
intersection as the example, the maximum queue length of each phase can be obtained on the basis of statistics probabilities
of traffic volume and states of signal phase. In this case, the delay model of actuated controlled intersection is proposed.
Example calculation shows that, under the condition of the fitting accuracy of mixture Gamma distribution beyond 95%, the
actuated control delay based on mixture Gamma distribution is more consistent with actual results.